Conversion tracking between two domains
I would like to track conversions between Domain A (we promote events on this site) and Domain B (Ticketmaster.co.nz events site).
The main goal, is to track who visited Domain A, and then made aPurchaseon Domain B.So far, I have a pixel setup on Domain B, and have set a filtered view in GA which is bringing in data from Domain A & B successfully.
My question is, as this is bringing in all data from both sites: How do I see in GA, what
Purchaseconversions are taking place on Domain B from Domain A?
The short answer is:
You must implement Google Analytics 4 (GA4) Cross-Domain Tracking to stitch the user session from Domain A to Domain B (Ticketmaster.co.nz).
This tells GA4 to treat the two distinct domains as a single, continuous user journey, preserving the original attribution source (Domain A’s visit) when the purchase event fires on Ticketmaster’s site.
Without this, the traffic from Domain A to Ticketmaster is incorrectly logged as a referral, breaking the crucial link needed for accurate attribution.
You’ll primarily use the GA4 Google Tag configuration, possibly managed via Google Tag Manager (GTM), to enable the automatic linker functionality which appends a unique ID (_gl) to the outbound link’s URL.
Once enabled, you can then use GA4’s standard reports, such as the Explorations or Advertising sections, to trace the conversion event back through the full session, attributing the purchase to the initial visit on Domain A.
The long answer is:
Your current setup, which successfully brings data into a filtered view in GA4 from both domains, is likely falling short in attribution because the transfer of a user between domains is being registered as a new session and a self-referral, as GA4’s default cookie is restricted to a single domain.
The technical solution is to enable GA4’s native cross-domain linking feature, which facilitates the passing of the unique Client ID between the domains, making the system recognize the user’s activity as one session.
You can configure this directly in the GA4 Admin panel under Data Streams and Configure tag settings, where you will add both Domain A and Ticketmaster.co.nz to the ‘Configure your domains’ list.
This action instructs the GA4 tag to automatically append a linker parameter (_gl) to any links pointing to the listed domains.
This _gl parameter contains the Client ID, which the receiving domain uses to continue the existing session rather than starting a new one.
This ensures the purchase on Ticketmaster.co.nz is correctly attributed to the traffic source of the visit on Domain A.
This approach is highly cost-effective as it leverages existing tools (GA4 and GTM, if used) with minimal custom code, providing an immediate fix to the attribution problem.
Furthermore, for a robust, server-side data synchronization and potentially a richer purchase data set, you should investigate leveraging the Ticketmaster APIs, specifically the Partner API, to potentially send authenticated, server-side Purchase event data directly to your server-side GTM container (via the GA4 Measurement Protocol) or directly to a data warehouse like BigQuery using the BigQuery API for advanced attribution modeling and reporting in Looker Studio, ensuring maximum data fidelity that is resilient to browser restrictions.
About The Author
